#include<iostream>
using namespace std;
int main(){
	int n,x,y,sy;
	cin>>n>>x>>y;
	sy=n-y/x;
	if(y%x!=0){
		sy=sy-1;
	}
	if(sy<0){
		sy=0;
	}
	cout<<sy<<endl;
	return 0;
}
